In the manufacture of pale wood rosin from southern pine stumpwood, crude rosin is extracted from the wood and then refined using solvent/solvent partitioning between aliphatic hydrocarbon and polar solvents. One of the by-products of this operation is a dark, high melting, largely aliphatic hydrocarbon-insoluble resin, hereinafter referred to as AHI resin.
AHI resin, available as Vinsol.RTM. resin from Hercules Incorporated, Wilmington, Del., is used in a wide variety of industrial applications including asphalt emulsions and concrete air-entrainment. Because the amount of wood rosin produced relative to tall oil and gum rosin is declining, the supply of AHI resin available for industrial applications is also declining.
Consequently, there is a need for a material which will perform in asphalt emulsions and concrete air-entrainment in a manner similar to that of AHI resin.